+ l = re.escape(langcode)
+
+ # Language preference from most to least priority
+ # Reference: section 5.6.3 of
+ # http://www.arte.tv/sites/en/corporate/files/complete-technical-guidelines-arte-geie-v1-05.pdf
+ PREFERENCES = (
+ # original version in requested language, without subtitles
+ r'VO{0}$'.format(l),
+ # original version in requested language, with partial subtitles in requested language
+ r'VO{0}-ST{0}$'.format(l),
+ # original version in requested language, with subtitles for the deaf and hard-of-hearing in requested language
+ r'VO{0}-STM{0}$'.format(l),
+ # non-original (dubbed) version in requested language, without subtitles
+ r'V{0}$'.format(l),
+ # non-original (dubbed) version in requested language, with subtitles partial subtitles in requested language
+ r'V{0}-ST{0}$'.format(l),
+ # non-original (dubbed) version in requested language, with subtitles for the deaf and hard-of-hearing in requested language
+ r'V{0}-STM{0}$'.format(l),
+ # original version in requested language, with partial subtitles in different language
+ r'VO{0}-ST(?!{0}).+?$'.format(l),
+ # original version in requested language, with subtitles for the deaf and hard-of-hearing in different language
+ r'VO{0}-STM(?!{0}).+?$'.format(l),
+ # original version in different language, with partial subtitles in requested language
+ r'VO(?:(?!{0}).+?)?-ST{0}$'.format(l),
+ # original version in different language, with subtitles for the deaf and hard-of-hearing in requested language
+ r'VO(?:(?!{0}).+?)?-STM{0}$'.format(l),
+ # original version in different language, without subtitles
+ r'VO(?:(?!{0}))?$'.format(l),
+ # original version in different language, with partial subtitles in different language
+ r'VO(?:(?!{0}).+?)?-ST(?!{0}).+?$'.format(l),
+ # original version in different language, with subtitles for the deaf and hard-of-hearing in different language
+ r'VO(?:(?!{0}).+?)?-STM(?!{0}).+?$'.format(l),
+ )
+
+ for pref, p in enumerate(PREFERENCES):
+ if re.match(p, versionCode):
+ lang_pref = len(PREFERENCES) - pref
+ break
+ else:
+ lang_pref = -1